Investigators in Baylor College of Medicine and the Department of Human Genetics at the School of Public Health, Health Sciences Center, Houston, TX will study the effects of beta adrenergic receptor activation on lipid and glucose metabolism in Hispanic men and women with and without non-insulin-dependent diabetes mellitus (NIDDM). The objective of these studies is to determine whether there is a predictable relationship between the beta 3-adrenergic receptor (AR) mutation, body fat distribution and lipid and glucose metabolism in Mexican-Americans. By using nutrition and exercise as experimental manipulations, we plan to determine the role of this mutation in the regulation of fuel substrate metabolism in health and its dysregulation in NIDDM.